High throughput screening methods in drug discovery traditionally have involved analyzing thousands of potential ligand compounds against a single target, e.g., a polypeptide, peptide, or a small chemical molecule, using microtiter assay methodology. Recent advances in high density array and microchip technology have reduced the number of these interactions and have increased the number of substances that can be assayed. In addition, the volume of compounds screened using such methods would be greatly increased by simultaneous detection of multiple targets interacting with multiple ligands.
Despite the great value that screening libraries of molecules has for identifying useful pharmaceutical compounds or improving the properties of a lead compound, the difficulties of screening such libraries has limited the impact that these methods should have made in drug discovery and development. Thus, there is a continued need for developing methods of simultaneously screening for multiple target-ligand interactions for drug discovery and the development of lead compounds.